Treatment of copper rich material



May 12, 1931. s. l. LEVY 1,805,100

' TREATMENT OF COPPER RICH MATERIAL Original Filed Mai'ch 1, 192a GOPPER- RICH RESIDUE' ROAST/N6 REACTION WITH H 6 man so Mam HGfl GYGLE 10 1v:

FREE SULPHUR.

FERRIC 0x10: HND Gnuguz Ina/v 0x10: To BLnsT FuRmcz.

QEZD W+ Patented May .12, 1931 UNITED STATES PATENT OFFICE STANLEY ISA-AG LEVY, LONDON, ENG-LAND rnmrmnm OF COPPER RICE MATERIAL ZOriginal application fled larch 1, 1988, Serial No. 258,489, and in Great Britain February 10, 1088. Divided and this application filed April Q6, 1929. Serial N 858,850.

' copending application Serial No. 258,439

{ ment of iron pyrites for the recovery therefrom of the metals and. also, if desired, of

filed 1st March 1928, relates to the treatment of copper-rich residues obtained in the treatthe sulphur.

In the specification of a co-pendinga plication Serial No. 259,317 filed 5th rch 1928, I have described a process of obtaining crude sulphur and pure sulphur by heating the pyrites in the absence of air leavin a mainly soluble residue and then reacting on the mainly soluble residue with hydrochloric acid. As a result of such reactions ferrous chloride and lead chloride pass into solution and sulphuretted hydrogen is evolved.

The residue from the treatment with hydrochloric acid solution of the mainly. soluble residue contains sulphides of. iron, co per and zinc, together with some free su hur and all the insoluble silicious matter rom the original pyrites and is hereinafter referred to as the co per-rich residue. This residuemay be sme ted directly for copper, but the other valuable elements are lost in this case. V

In accordance with the present invention, the copper-rich residue is subjected to an oxidizing treatment with air as aresult of which the subsequent operations are facili tated.

If the coppler-rich residues be roasted in air in a rnec ture not exceeding 600 0., the iron is converted to ferric oxide, and the zinc and'copper largely into the sulphates, while that part of the sui hur not 'so consumed is converted into su phur dioxide, The sulphur dioxide, which passes ofi from the furnace together with the nitrogen and excess of oxygen, is caused to react in known manner with sulphuretted hydrogen, obtained from the hydrochloric acid treatment of the mainly soluble residue referred to above, the amount of free oxygen in the gases being adj'usted. so that it is suficient to burn to sulphur in known manner any excess of hydrogen sulphide left afterthe sulphur dioxide I manner; or t gether with the copper and zinc solution obanical furnace at a tempera-' ess are indicated in the has reacted. The reactions are represented by the following equations By this means the greater part of the sulphur in the residue is obtained in the pureelemental condition. Such sulphur is collected in known manner.

The roasted residue is now extracted with water or dilute acid when about of the copper and-zinc present pass into the solutlon, from which they. may be removed by electrol is or precipitation in known mans e final residue of ferric oxide con- 1n the and again roasted, as a result of which the remainder of the copper and zinc are rendered soluble. The mixture is then a in extracted with water or dilute acid, an the final residue of insoluble iron oxide and silicious material sintered in the usual way. The copper and zinc may be removed from the solution so obtained directly by lysis or precipitation or otherwise in known is solution may be treated totained after the oxidizing roast described above; or it may be added to the reaction mixture of mainly soluble residue and hydroelectrochloric acid liquor referred to above, in which case the copper is precipitated with the residue. a ain, whilst the zincremains in the chlori e solution, and is recovered therefrom;

by a concentration process, as describedin the specification of my co-pending applica-' tions for patent Serial Nos. 259,317 and 257,091 filed 5th March 1928 and 25th Feb ruary 1928. v

The various stages respectively of the procaccompanying flow sheet.-

I claim,

A process for the recovery of copper and zinc from the residues left on treatment of the mainly soluble residue fromiron pyrites with hgdrochloric' acid, consisting 1n roasting suc residue inair, wnereb the 6 copper and zinc are converted into sulp ates, extracting the roasted residue thus obtained with solvent, chloridizing the residue left after extraction of theroasted residue by roasting with ferrous chloride, and extract- 10 ing the residue after the chloride roasting operation.

In testimony whereof I have aflixed my signature. I STANLEY ISAAC LEVY. 

